Many conventional spray deposition systems use highly pressurized air to help generate droplets of highly viscous fluids or fluids that have non-Newtonian properties. For example, some conventional systems use nozzle spraying, air-blast atomization techniques, and rotary atomization to create droplets although even these systems tend to have difficulties in creating the droplets and, more specifically, in creating droplets of a desired size, distribution and quantity.
Some mechanical spray deposition systems are able to atomize highly viscous and/or non-Newtonian fluids by using diverging surfaces, such as a pair of diverging pistons and/or a pair of counter-rotating rollers. These systems stretch fluid between the diverging surfaces until fluid filaments form. The applied strain or continuous stretching to the fluid filaments causes them to stretch until beyond the point at which the fluid filaments break up from capillary forces, meaning the fluid filaments exceed their capillary break-up point and break into droplets. The diverging surface-type spray deposition systems generally produce large volumes of spray droplets.
Typical with most spray depositions systems is the problem of overspray. Droplets are spread in many directions by the spray depositions systems. While many of the droplets are focused onto a desired substrate, some quantity of the spray deposits onto unintended surfaces. These surfaces can include the surrounding environment about the spray deposition system, including delicate control and electrical systems. Additionally, overspray reduces the efficiency of the spray deposition as any overspray is lost fluid that is not used for a desired or intended purpose.
In some situations, the atomized fluid may require heating or other treatment before being sprayed. These treatments can adversely affect the environment surrounding the spray deposition system, such as inducing undue heat stress on surrounding components. To protect the system components, oftentimes the conventional spray deposition systems simply cannot include elements that treat the fluid, like heating it, before the fluid is broken into droplets and sprayed.
Therefore, the spray deposition art would greatly benefit from systems and methods that can create of a quantity of droplets having a controlled size, distribution, or volume, that are directed in an intended direction to minimize overspray and have a controlled, isolated environment in which to manage and treat the fluid for atomization.